La thèse se décompose en deux parties. La première concerne l'utilisation du code de CFD atmosphérique Mercure Saturne pour estimer le potentiel éolien en terrain complexe. Une campagne de mesure a été menée par EDF pour disposer de données d'entrée et de validation. Une méthodologie a été développée utilisant des profils méso-échelle comme conditions limites du code CFD. Elle utilise la classification automatique pour réduire le nombre de simulations nécessaires au calcul du potentiel. La validation du code sur le cas connu de la colline d'Askervein, la méthodologie et les comparaisons avec les mesures sur le site complexe choisi sont présentées et discutées. La seconde partie concerne l'étude des sillages avec le code Mercure Saturne. Une méthode de représentation des efforts, exercés par les pales sur le vent, utilisant des termes sources a été implémentée. Ces derniers sont calculés par la méthode BEM. Deux comparaisons en soufflerie sont proposées pour la validation / This thesis is organized in two parts. The first part presents the use of the atmospheric CFD code Mercure Saturne to estimate the wind resource in complex terrain. A measurement campaign was led by EDF to obtain data for validation. A methodology was developed using meso-scale profiles as boundary conditions. Clustering of meteorological situations was used to reduce the number of simulations needed to calculate the wind resource. The validation of the code on the Askervein hill, the methodology and comparisons with measurements from the complex site are presented. The second part presents the modeling of wakes with the Mercure Saturne code. Forces, generated by the blades on the wind, are modeled by source terms, calculated by the BEM method. Two comparisons are proposed to validate the method : the first compares the numerical model with wind tunnel measurements from a small wind turbine, the second with measurements made on porous disks in an atmospheric boundary layer wind tunnel

Predation by olfactory meso-predators has a large impact on avian nest success, particularly for ground-nesting waterfowl. Olfactory predators rely on odors to locate their prey. Weather conditions (e.g. wind speed, humidity, and temperature), vegetation, and landscape features affect the dissipation rate of odors and could affect the foraging efficiency of olfactory predators. I conducted 2 studies to determine if weather and landscape impact predator foraging ability and behavior: a predator survey study and an artificial nest study. The objective of the predator survey was to investigate how landscape and weather conditions interact to influence the distribution of olfactory meso-predators [e.g. red foxes (Vulpes vulpes), skunks (Mephitis mephitis), and raccoons (Procyon lotor)] in their nightly foraging on the dike. Specifically, I examined how wind speed, wind orientation, temperature, and humidity affect the distribution, number, and species of olfactory meso-predators foraging on the Arthur V. Watkins Dike at Willard Bay State Park and Reservoir. The objective of the artificial nest study was to determine if weather, vegetation, or nest location relative to a large-scale surface feature have an effect on survival of artificial ground-nests in an area dominated by olfactory meso-predators. Artificial nests were placed on the dike throughout the summer of 2009. Spotlighting surveys for predators were conducted from August 2008 to August 2009. I found that section of the dike, time since study initiation, terrain type on the dike, wind speed, and vegetation height during daylight hours affected nest survival. The results indicated that predators formed olfactory search images in that nest survival decreased over the summer, while predator populations remained constant. I observed foxes, skunks, and raccoons while spotlighting for predators. After accounting for time, wind speed and direction were significant predictors of predators' nightly foraging activity with most predators observed when wind speeds were 2 to 4 m/s and winds were blowing from the northwest. Overall the model accounted for 75% of the nightly variation in predator numbers. Additionally, wind speed and direction impacted where predators were foraging. There were interspecific differences among predators in their responses to wind speed with raccoons being observed more than skunks and foxes when the wind was calm and blowing from the south. The results of the spotlighting data indicate that wind speed and direction have a strong effect on foraging activity. Overall, I concluded that wind speed affects predator foraging ability and behavior.

Workplace incidents result in significant human and financial costs. Despite these costs, it is estimated that less than 1% of organisational research focuses on issues concerning occupational health and safety (Barling & Zacharatos, 2000; Reason, 1990). Safety research has begun however to focus increasing attention on understanding the role that the wider organisational context, and in particular the role that safety climate, plays in influencing safety (Barling, Kelloway, & Iverson, 2003; Clarke, 2006a; Cox & Cheyne, 2000; Parker, Axtell, & Turner, 2001; Zohar, 2000). Safety climate refers to safety related policies, procedures and practices that signal the concern for safety (Griffin & Neal, 2000). The aim of the current program of research was to further understanding of the structure, antecedents and cross-level effects of safety climate. Specifically, this research aimed to better understand how organisational factors, and more specifically culture, influence safety climate and safety incidents. This knowledge is important as it assists organisations to purposively engineer stronger climates for safety and in doing so assists them to reduce the number of workplace incidents and accidents. The current program of research consists of three field-based studies. An overview of each study is provided below: Overview Study 1 Study 1 aimed to identify the safety climate schema for a sample of individuals working within the rail industry and explore whether safety climate schemas differ across individuals with and without leadership responsibilities. A proportional number of upper managers (n = 6), supervisors (n = 7) and workers (n = 12) were purposively sampled and interviewed. Interview data was analysed using Leximancer – an advanced computer assisted data mining tool. Results identified 10 emergent themes underlying a safety climate schema – many of these themes aligned closely with common safety climate factors in the academic literature. Results also showed differences between the safety factors that were dominant in the safety climate schemas of upper managers, supervisors and workers: upper managers were more closely associated with themes relating to ‘culture,’ and ‘people’; supervisors were more closely associated with themes relating to ‘corporate values,’ ‘management practices,’ and ‘safety communication’; whereas workers were more closely associated with themes relating to ‘procedures,’ and ‘safety training’. Results are discussed in relation to safety climate theory and in relation to how managers can use this knowledge to better communicate to the specific safety needs of different sub-groups. Overview Study 2 Study 2 aimed to better understand how perceived cultural profiles are related to safety. The Competing Values Framework adopted in this study proposes that four cultural types exist in unison in any organisation. Depending on the demands that are placed on the organisation, each type will be more or less dominant and each organisation will have a specific ‘cultural profile’ reflecting the strengths of each type. A cross-section of individuals (N = 368) working in high risk industries were sampled to identify the relationship between perceived cultural profiles and (1) psychological safety climate and (2) individual safety incidents. Modal Profile Analysis (MPA) identified four commonly perceived cultural profiles across the sample. A one-way MANOVA indicated that individuals who perceived their organisation had a strong human relations profile, or a dual focused human relations-rational goal profile, reported higher safety climate perceptions and fewer safety incidents. Comparably, individuals who perceived their organisation had a strong internal process profile, or a dual focused internal process-rational goal profile, reported lower safety climate perceptions and more safety incidents. These findings are discussed in terms of their theoretical contribution to the safety climate literature, and in relation to the practical importance that culture plays in influencing safety. Overview Study 3 Study 3 aimed to better understand how the culture of an organisation influences safety, and to explore the levels of analysis that are involved in this relationship. Specifically, this study examined the role that an internal process culture played in influencing safety climate; and in turn the mediating role that two sources of safety climate – business-unit safety climate and perceived supervisory safety climate – played in explaining the relationship between culture and individual-level outcomes (incidents, satisfaction and turnover intentions). Results showed that business-unit culture was related to business-unit safety climate; and that business-unit safety climate and perceived supervisory safety climate mediated the relationship between business-unit culture and incidents, satisfaction and turnover intentions. This research adds to the safety climate literature by providing evidence for the multi-level nature of the relationship between culture, safety climate and outcomes.

Customized cellular material is a relatively new area made possible by advancements in rapid manufacturing technologies. Rapid manufacturing is ideal for the production of customized cellular structure, especially on the meso scale, due to the size and complexity of the design. The means to produce this type of structure now exist, but the processes to design the structure are not well developed. The manual design of customized cellular material is not realistic due to the large number of features. Currently there are few tools available that aid in the design of this type of material. In this thesis, an automated tool to design customized cellular structure is presented.

Rapid prototyping (RP) can be used to make complex shapes with very little or even no constraint on the form of the parts. New design methods are needed for parts that can take advantage of the unique capabilities of RP. Although current synthesis methods can successfully solve simple design problems, practical applications with thousands to millions elements are prohibitive to generate solution for. Two factors are considered. One is the number of design variables; the other is the optimization method. To reduce the number of design variables, parametric approach is introduced. Control diameters are used to control all strut size across the entire structure by utilizing a concept similar to control vertices and Bezier surface. This operation allows the number of design variables to change from the number of elements to a small set of coefficients. In lattice structure design, global optimization methods are popular and widely used. These methods use heuristic strategies to search the design space and thus perform, as oppose to traditional mathematical programming (MP) methods, a better global search. This work propose that although traditional MP methods find local optimum near starting point, given a quick convergence rate, it will be more efficient to perform such method multiple times to integrate global search than using a global optimization method. Particle Swarm Optimization and Levenburg-Marquardt are chosen to perform the experiments.

Organizational researchers focus on group level variables such as organizational climate and organizational structure. The purpose of the current meso-level study is to examine the effects of the structure of an academic department on faculty members' job performance, job satisfaction, and prevalence of counterproductive work behavior (CWB), or harmful behaviors while at work. The sample consisted of 1135 full time faculty members working in 229 academic departments throughout the United States and Canada. Results of the study suggested that faculty members working in a more organically structured department report higher levels of job satisfaction. Additionally, productive faculty members working in more organically structured departments commit fewer instances of abusive behaviors than productive faculty members working in more mechanistically structured departments. The implications as well as limitations of the study are discussed.

Topology optimization tools are useful for distributing material in a geometric domain to match targets for mass, displacement, structural stiffness, and other characteristics as closely as possible. Topology optimization tools are especially applicable to additive manufacturing applications, which provide nearly unlimited freedom for customizing the internal and external architecture of a part. Existing topology optimization tools, however, do not take full advantage of the capabilities of additive manufacturing. Prominent tools use micro- or meso-scale voids or artificial materials to parameterize the topology optimization problem, but they use filters, penalization functions, and other schemes to force convergence to regions of fully dense (solid) material and fully void (open) space in the final structure as a means of accommodating conventional manufacturing processes. Since additive manufacturing processes are capable of fabricating intermediate densities (e.g., via porous mesostructures), significant performance advantages could be achieved by preserving and exploiting those features during the topology optimization process. Towards this goal, a topology optimization tool has been created by combining homogenization with parametric smoothing functions. Rectangular mesoscale voids are used to represent material topology. Homogenization is used to analyze its properties. B-spline based parametric smoothing functions are used to control the size of the voids throughout the design domain, thereby smoothing the topology and reducing the number of required design variables relative to homogenization-based approaches. Resulting designs are fabricated with selective laser sintering technology, and their geometric and elastic properties are evaluated experimentally. / text

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The advent of rapid manufacturing has enabled the realization of countless products that have heretofore been infeasible. From customized clear braces to jet fighter ducts and one-off dental implants, rapid manufacturing allows for increased design complexity and decreased manufacturing costs. The manufacturing capabilities of this process have evolved to the point that they have surpassed current design capabilities. Meso-scale lattice structures can now be built that contain more lattice struts than it is reasonable to efficiently define. This work has attempted to create a method for designing such lattice structures that is efficient enough to allow for the design of large or complex problems. The main hindrance to the design of complex meso-scale lattice problems is essentially the need to define the strut diameters. While it is obvious that a large design would contain more struts than can be specified by hand, designs also quickly surpass the current capabilities of computational optimization routines. To overcome this problem, a design method has been developed that uses a unit-cell library correlated to finite element analysis of the bounding geometry to tailor the structure to the anticipated loading conditions. The unit-cell library is a collection of base lattice primitives, or unit-cells, that have been specialized for certain applications. In this case, primitives have been created that perform best under the types of stress analyzed by finite element analysis. The effectiveness of this process has been demonstrated through several example problems. In all cases, the unit-cell library approach was able to create structures in less time than current methods. The resulting structures had structural performance slightly lower than similar models created through optimization methods, although the extent of this degradation was slight. The method developed in this work performs extremely well, and is able to create designs for even the most complex lattice structures. There is room for future development, however, in the streamlining of the design process and consideration of higher-order affects within unit-cells.

Thermodynamic and thermoeconomic aspects of 12.5 kW residential solar-thermal power generating systems suitable for distributed, decentralized power generation paradigm are presented in this thesis. The design of a meso-scale power system greatly differs from centralized power generation. As a result, this thesis provides guidance in the selection of the power cycle and operating parameters suitable for meso-scale power generation. Development of standard thermodynamic power cycle computer simulations provides means for evaluation of the feasibility of meso-scale solar-thermal power generation. The thermodynamic power cycles considered in this study are the Rankine cycle, the organic Rankine cycle with toluene, R123, and ethylbenzene as working fluids, the Kalina cycle, and the Maloney-Robertson cycle. From a strictly thermodynamic perspective, the cycles are evaluated based on first- and second-law efficiencies. Additionally, the study includes economic feasibility through thermoeconomic characterization that encompasses a meso-scale cost model for solar-thermal power generation systems. Key results from this study indicate that a R123 organic Rankine cycle is the most cost-effective cycle implementation for operating conditions in which the maximum temperature is limited below 240C. For temperatures greater than 240C and less than 375C, the toluene and ethylbenzne organic Rankine cycles outperform the other cycles. The highest first law efficiency of 28% of the Kalina cycle exceeds all other cycles at temperatures between 375C and 500C. However, when considering cycle cost and overall feasibility, including thermodynamic and thermoeconomic performance, the Maloney-Robertson and Kalina cycles have poor performance on a cost-to-efficiency basis.